Catalyst systems based on transition metal complexes for carbon monoxide copolymerization in an aqueous medium

ABSTRACT

Catalyst systems for the copolymerization of carbon monoxide and α-olefinically unsaturated compounds contain, as essential components,  
     a) a metal complex of the formula (I)  
                 
 
      where R 1  to R 4  are each linear or branched C 2 - to C 28 -alkyl, C 3 - to C 14 -cycloalkyl or alkylaryl where the alkyl moiety is of 1 to 28 carbon atoms and the aryl moiety is of 6 to 15 carbon atoms, each of which is substituted by at least one polar protic or ionic functional group based on elements of groups IVA to VIA of the Periodic Table of Elements, and  
     b) if required, one or more Lewis or protic acids or a mixture of Lewis and protic acids.

[0001] The present invention relates to catalyst systems for thecopolymerization of carbon monoxide and α-olefinically unsaturatedcompounds, containing, as essential components,

[0002] a) a metal complex of the formula (I)

[0003]  where

[0004] G is —(CR^(b) ₂)_(r)—, —(CR^(b) ₂)_(s)—Si(R^(a))₂—(CR^(b)₂)_(t)—, —A′—O—B′— or —A′—Z(R⁵)—B′—,

[0005] R⁵ is hydrogen, or is C₁- to C₂₈-alkyl, C₃- to C₁₄-cycloalkyl,C₆- to C₁₅-aryl or alkylaryl where the alkyl radical is of 1 to 20carbon atoms and the aryl radical is of 6 to 15 carbon atoms, each ofwhich is unsubstituted or substituted by functional groups based on theelements of groups IVA, VA, VIA or VIIA of the Periodic Table ofElements, or is —N(R^(b))₂, —Si(R^(c))₃ or a radical of the formula II

[0006]  where

[0007] q is an integer from 0 to 20 and the further substituents in (II)have the same meanings as in (I),

[0008] A′ and B′ are each —(CR^(b) ₂)_(r′)—, —(CR^(b)₂)_(s)—Si(R^(a))₂—(CR^(b) ₂)_(t)—, —N(R^(b))—, an r′-, s- or t-atomcomponent of a ring system or, together with Z, an (r′+1)-, (s+1)- or(t+1)-atom component of a heterocyclic structure,

[0009] R^(a) independently of one another, are each C₁- to C₂₀-alkyl,C₃- to C₁₀-cycloalkyl, C₆- to C₁₅-aryl or alkylaryl where the alkylmoiety is of 1 to 10 carbon atoms and the aryl moiety is of 6 to 15carbon atoms,

[0010] R^(b) is the same as R^(a) or is hydrogen or Si(R^(c))₃,

[0011] R^(c) is C₁- to C₂₀-alkyl, C₃- to C₁₀-cycloalkyl, C₆- to C₁₅-arylor alkylaryl where the alkyl moiety is of 1 to 10 carbon atoms and thearyl moiety is of 6 to 15 carbon atoms,

[0012] r is 1, 2, 3 or 4,

[0013] r′ is 1 or 2,

[0014] s and t are each 0, 1 or 2, where 1≦s+t≦3,

[0015] z is a nonmetallic element from group VA of the Periodic Table ofElements,

[0016] M is a metal selected from the group VIIIB, IB or IIB of thePeriodic Table of Elements,

[0017] E¹ and E² are each a nonmetallic element from group VA of thePeriodic Table of Elements,

[0018] R¹ to R⁴ are each linear or branched C₂- to C₂₈-alkyl, C₃- toC₁₄-cycloalkyl or alkylaryl where the alkyl moiety is of 1 to 28 carbonatoms and the aryl moiety is of 6 to 15 carbon atoms, each of which issubstituted by at least one polar protic or ionic functional group basedon elements of groups IVA to VIA of the Periodic Table of Elements,

[0019] L¹ and L² are formally charged or neutral ligands,

[0020] X are formally monovalvent or polyvalent anions,

[0021] p is 0, 1, 2, 3 or 4,

[0022] m and n are each 0, 1, 2, 3 or 4,

[0023] and p=m×n, and

[0024] b) if required, one or more Lewis or protic acids or a mixture ofLewis and protic acids.

[0025] The present invention furthermore relates to the use of thesecatalyst systems for the preparation of linear, alternating copolymersof carbon monoxide and α-olefinically unsaturated compounds andprocesses for the preparation of said copolymers in an aqueous medium.

[0026] Processes, catalyzed by transition metals, for the preparation oflinear, alternating copolymers of carbon monoxide and α-olefinicallyunsaturated compounds, also referred to for short as carbon monoxidecopolymers or polyketones, are known. For example, a cis-palladiumcomplex chelated with bidentate phosphine ligands, [Pd(Ph₂P(CH₂)₃PPh₂)](OAc)₂ (Ph=phenyl, Ac=acetyl), is used in EP-A 0 121 965. The carbonmonoxide copolymerization can be carried out in suspension, as describedin EP-A 0 305 011, or in the gas phase, for example according to EP-A 0702 045 Frequently used suspending media are on the one hand lowmolecular weight alcohols, in particular methanol (also see EP-A 0 428228), and on the other hand nonpolar or polar aprotic liquids, such asdichloromethane, toluene or tetrahydrofuran (cf. EP-A 0 460 743 and EP-A0 590 942). Complex compounds having bisphosphine chelate ligands whoseradicals on the phosphorus are aryl or substituted aryl groups haveproven particularly suitable for said polymerization processes.Accordingly, 1,3-bis(diphenylphosphine)propane and1,3-bis[di(o-methoxyphenyl)phosphine)]propane are particularlyfrequently used as chelate ligands (also see Drent et al., Chem. Rev.,1996, 96, 663-681). Usually, the carbon monoxide copolymerization iscarried out in the stated cases in the presence of acids.

[0027] The carbon monoxide copolymerization in low molecular weightalcohols, such as methanol, has the disadvantage that the carbonmonoxide copolymer formed has high absorptivity for these liquids and upto 80% by volume of, for example, methanol are bound or absorbed by thecarbon monoxide copolymer. Accordingly, a large amount of energy isrequired to dry the carbon monoxide copolymers and to isolate them inpure form. Another disadvantage is that residual amounts of alcoholstill remain in the carbon monoxide copolymer even after an intensivedrying process. Molding materials prepared in this manner are thereforeunsuitable from the outset for use as packaging material for food. EP-A0 485 035 proposes the use of additions of water in amounts of from 2.5to 15% by weight to the alcoholic suspending medium in order toeliminate the residual amounts of low molecular weight alcohol in thecarbon monoxide copolymer. However, this procedure too does not lead tomethanol-free copolymers. The use of halogenated hydrocarbons oraromatics, such as dichloromethane or chlorobenzene or toluene, on theother hand, gives rise to problems, in particular in handling anddisposal.

[0028] For overcoming the disadvantages associated with said suspendingmedia, Jiang and Sen, Macromolecules, (1994), 27, 7215-7216, describethe preparation of linear, alternating carbon monoxide copolymers inaqueous systems using a catalyst system consisting of [Pd(CH₃CN)₄](BF₄)₂ and 1,3-bis [di(3-sulfophenyl)phosphine]propane as awater-soluble chelate ligand. However, the catalyst activity achieved isvery low and therefore unsuitable for a large-scale industrialpreparation.

[0029] Verspui et al., Chem. Commun., 1998, 401-402, succeed, incomparison with Jiang and Sen, in increasing the catalyst activity inthe copolymerization of carbon monoxide and ethene, by using saidchelate ligand in substantially purer form, owing to an improvedsynthesis method (cf. also Hermann et al., Angew. Chem. Int. Ed. Engl.,1995, 34, 811 et seq.). Furthermore, the presence of a Bronsted acid isrequired in order to obtain catalyst activities improved in comparisonwith Jiang and Sen. Although the chelate ligand1,3-bis(di(3-sulfophenyl)phosphine]propane can be prepared in purer formwith the aid of an improved synthesis method, this by no meansdemonstrates how it is possible to obtain suitable chelate ligandshaving other substitution patterns. Thus, the water-soluble transitionmetal complexes described are limited exclusively to sulfonated aromaticsubstituents on the phosphorus. The preparation of these chelate ligandsfurthermore requires the handling of very aggressive substances, such asboric acid, concentrated sulfuric acid and oleum. An extension to othersystems is in principle not possible, owing to the given structure.

[0030] It is therefore desirable to be able to use, for thecopolymerization of carbon monoxide an α-olefinically unsaturatedcompounds in aqueous systems, catalyst systems which from the outsetpermit a large number of different substituents on the chelate ligandand at the same time enable constantly good reproducibility incombination with high efficiency.

[0031] It is an object of the present invention to provide, for thepreparation of linear, alternating carbon monoxide copolymers, catalystsystems which are suitable for the copolymerization in an aqueousmedium. It is a further object of the present invention to provideprocesses which give, with reproducibly good catalyst activity, linear,alternating carbon monoxide copolymers in an aqueous medium in thepresence of said catalyst systems.

[0032] We have found that these objects are achieved by the catalystsystems defined at the outset and by their use for the preparation oflinear, alternating carbon monoxide copolymers and a process for thepreparation of these carbon monoxide copolymers.

[0033] Preferred novel catalyst systems contain, as active compounds

[0034] a) a metal complex of the formula (Ia)

[0035]  where

[0036] G is —(CR^(b) ₂)_(r)— or —(CR^(b) ₂)—N(R⁵)—(CR^(b) ₂)—,

[0037] R^(b) is hydrogen, C₁- to C₁₀-alkyl or C₆- to C₁₀-aryl,

[0038] r is 1, 2, 3 or 4,

[0039] R⁵ is hydrogen, C₁- to C₁₀-alkyl, C₃- to C₁₀-cycloalkyl, C₆- toC₁₅-aryl, or C₁- to C₁₀-alkyl, C₃- to C₁₀-cycloalkyl or C₆- to C₁₅-aryl,each of which is substituted by functional groups based on elements ofgroups IVA, VA, VIA and VIIA of the Periodic Table of Elements,

[0040] M is palladium or nickel

[0041] E¹ and E² are each phosphorus,

[0042] R¹ to R⁴ are each a linear, branched or carbocycle-containing C₂-to C₂₈-alkyl unit or C₃- to C₁₄-cycloalkyl unit which has at least oneterminal or internal hydroxyl, amino, carboxyl, phosphoric acid,ammonium or sulfo group, or an alkylaryl group where the alkyl moiety isof 1 to 20 carbon atoms and the aryl moiety is of 6 to 15 carbon atoms,the alkyl or aryl moiety being substituted by at least one hydroxyl,carboxyl, amino acid, phosphoric acid, ammonium or sulfo group,

[0043] L¹ and L² are each acetate, trifluoroacetate, tosylate or halide,and

[0044] b) sulfuric acid, p-toluenesulfonic acid, tetrafluoroboric acid,trifluoromethanesulfonic acid, perchloric acid or trifluoroacetic acidas the protic acid or boron trifluoride, antimony pentafluoride or atriarylborane as the Lewis acid.

[0045] In a further embodiment, a preferred catalyst system is one inwhich R¹ to R⁴ in the metal complex (I) are each C₂- to C₂₈-alkyl, C₃-to C₁₄-cycloalkyl or alkylaryl where the alkyl moiety is of 1 to 28carbon atoms and the aryl moiety is of 6 to 15 carbon atoms, each ofwhich is substituted by at least one free carboxyl or sulfo group, thepresence of external Lewis or protic acids b) being completely dispensedwith.

[0046] In principle, bidentate chelate ligands of the formula (R¹)(R²)E¹—G—E²(R³) (R⁴) (III) in which the substituents and indices havethe abovementioned meanings are suitable as a component of thetransition metal complexes (I) or of the novel catalyst system.

[0047] The bridging structural unit G in the metal complexes (I) or inthe chelate ligands (III) of the novel catalyst system consists ingeneral of monoatomic or polyatomic bridge segments. A bridgingstructural unit is understood in principle as meaning a group whichlinks the elements E¹ and E² to one another. Such structural unitsinclude, for example, substituted or unsubstituted alkylene chains orthose alkylene chains in which an alkylene unit is replaced by asilylene group, an amino or phosphino group or an ether oxygen.

[0048] Preferred monoatomically bridged structural units are thosehaving a bridging atom from the group IVA of the Periodic Table ofElements, such as —C(R^(b))₂— or —Si(R^(a))₂—, where R^(a),independently of one another, are each in particular linear or branchedC₁- to C₁₀-alkyl, for example methyl, ethyl, isopropyl or tert-butyl,C₃- to C₆-cycloalkyl, such as cyclopropyl or cyclohexyl, C₆- toC₁₀-aryl, such as phenyl or naphthyl, C₆- to C₁₀-aryl substituted byfunctional groups based on the nonmetallic elements of groups IVA, VA,VIA or VIIA of the Periodic Table, for example tolyl,(trifluoromethyl)phenyl, dimethylaminophenyl, p-methoxyphenyl orpartially halogenated or perhalogenated phenyl, or aralkyl where thealkyl moiety is of 1 to 6 carbon atoms and the aryl moiety is of 6 to 10carbon atoms, for example benzyl, and R^(b) is in particular hydrogenand may furthermore have the meanings stated above for R^(a). R^(a) isin particular methyl and R^(b) is in particular hydrogen.

[0049] Among the polyatomically bridged systems, the diatomically,triatomically and tetraatomically bridged structural units are to besingled out, the triatomically bridged systems generally preferablybeing used.

[0050] Suitable triatomically bridged structural units are based ingeneral on a chain of carbon atoms, for example propylene (—CH₂CH₂CH₂—),or on a bridge unit having a hetero atom from group IVA, VA or VIA ofthe Periodic Table of Elements, such as silicon, nitrogen, phosphorus oroxygen, in the chain skeleton.

[0051] The bridge carbon atom can in general be substituted by C₁- toC₆-alkyl, such as methyl, ethyl or tert-butyl, by C₆- to C₁₀-aryl, suchas phenyl, or by functional groups based on elements of groups IVA, VA,VIA or VIIA of the Periodic Table of Elements, for exampletriorganosilyl, dialkylamino, alkoxy, hydroxyl or halogen. Suitablesubstituted propylene bridges are, for example, those having a methyl,phenyl, hydroxyl, trifluoromethyl, ω-hydroxyalkyl or methoxy group inthe 2 position.

[0052] Among the polyatomically bridged structural units having a heteroatom in the chain skeleton, advantageously used compounds are those inwhich Z is nitrogen or phosphorus, in particular nitrogen (cf. alsoformula (I)). R⁵ on Z may be in particular hydrogen, linear or branchedC₁- to C₂₈-alkyl, in particular C₁- to C₂₀-alkyl, such as methyl, ethyl,isopropyl, tert-butyl, n-hexyl or n-dodecyl, C₃- to C₁₄-cycloalkyl, inparticular C₃- to C₈-cycloalkyl, such as cyclopropyl or cyclohexyl, C₆-to C₁₅-aryl, in particular C₆- to C₁₀-aryl, for example phenyl, oralkylaryl where the alkyl radical is of 1 to 20 carbon atoms and thearyl radical is of 6 to 10 carbon atoms, for example benzyl.

[0053] Said alkyl and aryl radicals include both ,unsubstituted andsubstituted compounds. The substituted compounds may contain, forexample, functional groups based on the elements of groups IVA, VA, VIAor VIIA of the Periodic Table of Elements. Suitable, inter alia, aretriorganosilyl groups, such as trimethylsilyl ortert-butyldiphenylsilyl, carboxyl or carboxylic acid derivatives such asesters or amides, primary, secondary or tertiary amino, such asdimethylamino or methylphenylamino, nitro, hydroxyl, alkoxy, such asmethoxy or ethoxy, sulfonate group or halogen, such as fluorine,chlorine or bromine. For the purpose of the present invention, arylincludes substituted or unsubstituted heteroaryl, for example pyridyl orpyrrolyl. Alkyl radicals R⁵ also include long-chain alkylene having 12to 22 carbon atoms in the chain, which may also have polar protic orionic functional groups, such as sulfo, carboxyl, hydroxyl, amino orammonium, for example in the terminal position.

[0054] Other preferred radicals R⁵ are those which have anelectron-attracting substituent. Examples of suitableelectron-attracting substituents are alkyl groups having one or moreelectron-attracting radicals, such as fluorine, chlorine, nitrile ornitro, α or β to Z. Also suitable are aryl groups having saidelectron-attracting radicals and, as radicals bonded directly to Z, alsothe nitrile, sulfonate and nitro groups. Examples of suitableelectron-attracting alkyl radicals are trifluoromethyl, trichloroethyl,difluoromethyl, 2,2,2-trifluoroethyl, nitromethyl and cyanomethyl.Examples of suitable electron-attracting aryl radicals are m-, p- ando-fluoro- and chlorophenyl, 2,4-difluorophenyl, 2,4-dichlorophenyl,2,4,6-trifluorophenyl, 3,5-bis(trifluoromethyl)phenyl, nitrophenyl,2-chloro-5-nitrophenyl and 2-bromo-5-nitrophenyl. In this context,carbonyl units are also suitable as R⁵ so that, if Z is nitrogen, Z andR⁵ form a carboxamido functional group. Examples of suitable radicals ofthis type are acetyl and trifluoroacetyl.

[0055] R⁵ is particularly preferably tert-butyl, phenyl, p-fluorophenyl,trifluoromethyl, 2,2,2-trifluoroethyl, pentafluorophenyl,3,5-bis(trifluoromethyl)phenyl and ortho-difluorophenyl, e.g.3,4-difluorophenyl, meta-difluorophenyl, e.g. 2,4-difluorophenyl, orpara-difluorophenyl, e.g. 2,5-difluorophenyl.

[0056] Suitable units A′ and B′ in the formulae (I) to (III) are C₁- toC₄-alkylene units in substituted or unsubstituted form, for examplemethylene, ethylene, propylene or ethylidene, propylidene andbenzylidene. Methylene, ethylene, ethylidene or benzylidene ispreferably used, particularly preferably methylene.

[0057] A′ and B′ may also be a monoatomic, diatomic, triatomic ortetraatomic component of an aliphatic or aromatic ring system. Forexample, A′ and B′ may be a methylene or ethylene unit of a cyclopropyl,cyclopentyl or cyclohexyl ring. Suitable ring systems are also aliphaticand aromatic heterocycles.

[0058] A′ and B′ may furthermore be a component of a heterocycle whichis formed from the components A′—Z—R⁵ or B′—Z—R⁵, i.e. A′—Z—R⁵ orB′—Z—R⁵ may be, for example, a substituted or unsubstituted pyrrolidineor piperidine ring.

[0059] Suitable chelating atoms E¹ and E² are, independently of oneanother, the nonmetallic elements of group VA of the Periodic Table ofElements, nitrogen and phosphorus being preferably used, in particularphosphorus. In a preferred embodiment, E¹ and E² in the compounds (I)and (III) are each phosphorus.

[0060] In the novel catalyst systems, R¹ to R⁴ are each C₂- toC₂₈-alkyl, preferably C₃- to C₂₀-alkyl, C₃- to C₁₄-cycloalkyl,preferably C₃- to C₈-cycloalkyl, or alkylaryl where the alkyl moiety isof 1 to 28, preferably 3 to 20, carbon atoms and the aryl moiety is of 6to 15, preferably 6 to 10, carbon atoms, each of which is substituted bya polar protic or ionic functional group based on elements of groups IVAto VIA of the Periodic Table of Elements. R¹ to R⁴ are preferably eachlinear, branched or carbocycle-containing C₂- to C₂₈-alkyl units or C₃-to C₁₄-cycloalkyl units which have at least one terminal or internalhydroxyl, carboxyl, phosphoric acid, ammonium, amino acid or sulfogroup, or alkylaryl where the alkyl moiety is of 1 to 28 carbon atomsand the aryl moiety is of 6 to 15 carbon atoms, the alkyl or aryl moietybeing substituted by at least one hydroxyl, carboxyl, phosphoric acid,ammonium, amino acid or sulfo group.

[0061] It is also possible to use salts of the carboxylic, phosphoric,amino or sulfonic acids. Suitable salts are, for example alkali metal oralkaline earth metal salts, such as sodium, potassium or magnesiumcarboxylates or sulfonates.

[0062] Particularly suitable opposite ions for said ammonium radicalsare non-nucleophilic anions, as also used for the transition metalcomplexes (I) (cf. anions X). For example, p-toluenesulfonate,tetrafluoroborate, trichloroacetate and hexafluorophosphate areparticularly suitable.

[0063] Particularly suitable alkyl radicals R¹ to R⁴ are, for example,alkylene units having one or two terminal hydroxyl, carboxyl, sulfo orammonium groups. Furthermore, R¹ to R⁴ may also have more than two polargroups, for example four or six hydroxyl, ammonium or carboxyl groups.Accordingly, R¹ to R⁴ in a chelate compound (III) may each also havedifferent functional groups. R¹ to R⁴ may also have functional groups innumbers differing from one another. Suitable radicals R¹ to R⁴ are, forexample, compounds of 25 the formula (IV):

—(CR^(d) ₂)_(k)—(T)₁—(CR^(d) ₂)_(k′)—Y  (IV)

[0064] where

[0065] R^(d) has the same meaning as R^(b) or is Y,

[0066] T is C₃- to C₁₀-cycloalkylene, in particular C₃- toC₆-cycloalkylene, or C₆- to C₁₅-arylene, in particular C₆- toC₁₀-arylene, unsubstituted or substituted by R^(d) or Y,

[0067] k is from 0 to 20 if 1 is 0 or 1 and T is cycloalkyl, and is from1 to 20 if 1 is 1 and T is aryl,

[0068] k′ is from 0 to 20,

[0069] 1 is 0 or 1 and

[0070] Y is a polar protic or ionic functional group based on elementsof groups IVA to VIA of the Periodic Table of Elements.

[0071] Suitable radicals Y are the hydroxyl, amino acid, carboxyl,phosphoric acid, ammonium and sulfo group. Preferred cycloaliphaticradicals T are cyclopentyl and cyclohexyl and the preferred aryl orarylene unit T is phenyl or phenylene, respectively. As a rule, k isfrom 2 to 20, preferably from 3 to 18, and k′ is preferably from 0 to10, in particular from 1 to 8.

[0072] The preparation of suitable propylene-bridged compounds havingchelate ligands can be carried out, for example, starting from thecommercially available 1,3-dibromopropane. A double Arbuzov reaction,for example with triethyl phosphite, gives 1,3-bisphosphonic acidderivatives, which can be converted by reduction, as described inMethoden der organischen Chemie (Houben-Weyl), 4th Edition, VolumeXII/1, Part 1, Georg Thieme Verlag, 1963, page 62, into1,3-diphosphinopropane. Suitable reducing agents are, for example,lithium aluminum hydride and diisobutyl aluminum hydride. Via ahydrophosphination reaction with functionalized olefins,1,3-diphosphinopropane provides a flexible route to substitutedbisphosphines. The hydrophosphination takes place in general via a freeradical mechanism and can be initiated thermally, photochemically orwith the aid of a free radical initiator. For thermal initiation, ingeneral temperatures of from 20 to 100° C. and pressures of from 0.1 to5 bar are required. A suitable free radical initiator is, for example,di-tert-butyl peroxide or azobisisobutyronitrile. For photochemicalinitiation, as a rule the UV radiation of a high-pressure mercury lampover a period of from 2 to 48 hours is sufficient for quantitativehydrophosphination. In general, anti-Markovnikov products are obtainedin the hydrophosphination by means of processes involving free radicalinitiation.

[0073] For the preparation of chelate ligands having radicals R¹ to R⁴which carry carboxyl groups, it is proven advantageous to start fromolefinically unsaturated compounds which have been derivatized withcorresponding carboxylic ester groups and to use them in thehydrophosphination reaction. The free carboxylic acids can then beobtained by means of hydrolysis by known methods.

[0074] In addition, suitable compounds having chelate ligans can also beprepared under conditions of acid catalysis. The products obtained bythis process are often present as a mixture owing to the isomerizationof the olefinic double bond under the acidic reaction conditions. Thehydrophosphination step is described, for example, in Methoden derorganischen Chemie (Houben-Weyl), 4th Edition, Volume XII/1, Part 1,Georg Thieme Verlag, 1963, pages 25 to 28.

[0075] In general, all olefins covered by this class of compounds aresuitable for said hydrophosphination reaction, provided that they have apolar protic or ionic functional group. For example, propylene radicalsand C₄- to C₂₈-alkenes having at least one internal or terminal doublebond, which have at least one hydroxyl, amino acid, carboxyl, phosphoricacid, ammonium or sulfo group, are suitable. Also suitable are olefiniccompounds having aromatic radicals, it being possible for the functionalgroup to be present both on the aliphatic and on the aromatic radical,for example 4-(1-pentenyl)benzoic acid or 3-phenylpent-5-enecarboxylicacid. Furthermore, olefinic compounds having aliphatic carbocyclicstructures in the alkylene chain are suitable as substituents. Cyclicolefins, such as cyclohexen-3-ol or cycloocten-4-ol, may also be used.It is of course also possible to employ olefins having a plurality ofpolar protic or ionic functional groups. Suitable alkenes having anα-olefinic double bond are preferably used in the hydrophosphinationreaction of the α, ω-bisphosphines. Suitable alkenes of this typeinclude, for example, hetero atom-containing α-olefins, such as(meth)acrylates or (meth)acrylamides and homoallyl or allyl alcohols.

[0076] Particularly preferably used radicals R¹ to R⁴ are those in whichthe hydrophilic character induced by the polar protic or ionicfunctional groups is sufficient to make the metal complex (I) completelywater-soluble. The larger the number of functional groups on theradicals R¹ to R⁴, the greater may be the lipophilic aliphatic oraliphatic-aromatic fraction. Examples of preferred radicals R¹ to R⁴each having a hydroxyl group are those having 2 to 15 carbon atoms inthe alkyl unit.

[0077] In a particularly preferred embodiment of the chelate ligand(III), alkyl substituents R¹ to R⁴ having a hydroxyl group are each of 4to 12, in particular 4 to 7, carbon atoms, alkyl substituents R¹ to R⁴having a carboxyl group are each of 4 to 15, in particular 5 to 12,carbon atoms, alkyl substituents R¹ to R⁴ having a sulfo group are eachof 4 to 18, in particular 5 to 15, carbon atoms and alkyl substituentsR¹ to R⁴ having an ammonium group are each of 4 to 22, in particular 5to 20, carbon atoms.

[0078] Examples of suitable chelate ligands (III) are

[0079] 1,3-bis(di-5-hydroxypentyl)phosphinopropane,

[0080] 1,3-bis(di-6-hydroxyhexyl)phosphinopropane,

[0081] 1,3-bis(di-7-hydroxyheptyl)phosphinopropane,

[0082] 1,3-bis(di-8-hydroxyoctyl)phosphinopropane,

[0083] 1,3-bis(di(3-hydroxycyclopentyl)propyl)phosphinopropane,

[0084] 1,3-bis[di-5-sulfopentyl]phospinopropane,

[0085] 1,3-bis[di-6-sulfohexyl]phosphinopropane,

[0086] 1,3-bis[di-7-sulfoheptyl]phosphinopropane,

[0087] 1,3-bis[di-8-sulfooctyl]phosphinopropane,

[0088] 1,3-bis[di(3-(sulfocyclopentyl)propyl]phosphinopropane,

[0089] 1,3-bis(di-5-pentanoyl)phospinopropane,

[0090] 1,3-bis(di-6-hexanoyl)phospinopropane,

[0091] 1,3-bis(di-7-heptanoyl)phosphinopropane,

[0092] 1,3-bis(di-8-octanoyl)phosphinopropane,

[0093] bis[(di-5-hydroxypentyl)phospinomethyl]phenylamine,

[0094] bis[(di-6-hydroxyhexyl)phosphinomethyl]phenylamine,

[0095] bis[(di-7-hydroxyheptyl)phosphinomethyl]phenylamine,

[0096] bis[(di-8-hydroxyoctyl)phosphinomethyl]phenylamine,

[0097] bis[(di(3-hydroxycyclopentyl)propyl]phenylamine,

[0098] bis[(di-5-(sulfopentyl)phosphinomethyl]phenylamine,

[0099] bis[(di-6-(sulfohexyl)phospinomethyl]phenylamine,

[0100] bis[(di-7-sulfoheptyl)phosphinomethyl]phenylamine,

[0101] bis[(di-8-sulfooctyl)phosphinomethyl)phenylamine,

[0102] bis[(di(3-sulfocyclopentyl)propyl)phospinomethyl]phenylamine,

[0103] bis[(di-5-pentanoyl)phospinomethyl]phenylamine

[0104] bis[(di-6-hexanoyl)phospinomethyl]phenylamine,

[0105] bis[(di-7-heptanoyl)phosphinomethyl]phenylamine and

[0106] bis[(di-8-octanoyl)phosphinomethyl]phenylamine.

[0107] Particularly preferred among said compounds having chelateligands are those in which R¹ to R⁴ are each a hydroxyl- orcarboxyl-substituted hexyl, octyl, cyclopentyl or cyclohexyl radical.

[0108] Suitable metals M of the novel catalyst system are the metals ofgroups VIIIB, IB and IIB of the Periodic Table of Elements, i.e. mainlythe platinum metals, such as ruthenium, rhodium, osmium, iridium andplatinum and very particularly preferably palladium, in addition toiron, cobalt and nickel. In the complexes (I), the metals may beformally neutral, formally bearing a single positive charge orpreferably formally bearing a double positive charge.

[0109] Suitable formally charged inorganic ligands L¹ and L² arehydride, halides, sulfates, phosphates or nitrates. Carboxylates orsalts of organic sulfonic acids, such as methylsulfonate,trifluoromethylsulfonate or p-toluenesulfonate, are also suitable. Amongthe salts of organic sulfonic acids, p-toluenesulfonate is preferred.Preferred formally charged ligands L¹ and L² are carboxylates,preferably C₁- to C₂₀-carboxylates, in particular C₁- toC₇-carboxylates, e.g. acetate, trifluoroacetate, propionate, oxalate,citrate or benzoate. Acetate is particularly preferred.

[0110] Suitable formally charged organic ligands L¹ and L² are alsoaliphatic C₁- to C₂₀-radicals, cycloaliphatic C₃- to C₃₀-radicals, C₇-to C₂₀-aralkyl radicals having C₆- to C₁₄-aryl radicals and C₁- toC₆-alkyl radicals and aromatic C₆ to C₂₀ radicals, for example methyl,ethyl, propyl, isopropyl, tert-butyl, n-pentyl, isopentyl, cyclohexyl,benzyl, phenyl and aliphatically or aromatically substituted phenylradicals.

[0111] Suitable formally neutral radicals L¹ and L² are in general Lewisbases, i.e. compounds having at least one free electron pair.Particularly suitable are Lewis bases whose free electron pair or whosefree electron pairs is or are present on a nitrogen or oxygen atom, forexample nitriles, R—CN, ketones, ethers, alcohols or water. C₁- toC₁₀-nitriles, such as acetonitrile, propionitrile or benzonitrile, orC₂- to C₁₀-ketones, such as acetone or acetylacetone, or C₂- toC₁₀-ethers, such as dimethyl ether, diethyl ether or tetrahydrofuran,are preferably used. In particular, acetonitrile, tetrahydrofuran orwater is used.

[0112] In principle, the ligands L¹ and L² may be present in any desiredligand combination, i.e. the metal complex (I) may contain, for example,a nitrate and an acetate radical, a p-toluenesulfonate and an acetateradical or a nitrate and a formally charged organic ligand, such astert-butyl. L¹ and L² are preferably present as identical ligands in themetal complexes.

[0113] Depending on the formal charge of the complex fragment containingthe metal M, the metal complexes contain anions X. If the M-containingcomplex fragment is formally neutral, the novel complex (I) contains noanion X. It is advantageous to use anions X which have very littlenucleophilic character, i.e. very little tendency to have a stronginteraction, whether ionic, coordinate or covalent, with the centralmetal M.

[0114] Suitable anions X are, for example, perchlorate, sulfate,phosphate, nitrate and carboxylates, for example acetate,trifluoroacetate, trichloroacetate, propionate, oxalate, citrate orbenzoate, and conjugated anions of organosulfonic acids, such asmethylsulfonate, trifluoromethylsulfonate and para-toluenesulfonate, andfurthermore tetrafluoroborate, tetraphenylborate,tetrakis(pentafluorophenyl)borate, tetrakis[bis(3,5-trifluoromethyl)phenyl]borate, hexafluorophosphate,hexafluoroarsenate or hexafluoroantimonate. Perchlorate,trifluoroacetate, sulfonates, such as methylsulfonate,trifluoromethylsulfonate or p-toluenesulfonate, tetrafluoroborate orhexafluorophosphate are preferably used, in particulartrifluoromethylsulfonate, trifluoroacetate, perchlorate orp-toluenesulfonate.

[0115] Examples of suitable defined transition metal complexes are:

[0116] [1,3-bis(di-5-hydroxypentyl)phospinopropane]palladium(II)acetate,

[0117] [1,3-bis(di-6-hydroxyhexyl)phosphinopropane]palladium(II)acetate,

[0118][1,3-bis(di(3-hydroxycyclopentyl)propyl)phosphinopropane]-palladium(II)acetate,

[0119] [1,3-bis(di-8-hydroxyoctyl)phospinopropane]palladium(II) acetateand

[0120][1,3-bis(di-3-hydroxycyclohexyl)propyl)phospinopropane]-palladium(II)acetate.

[0121] The transition metal complexes described are soluble at least insmall amounts in water. As a rule, these metal complexes are readily tovery readily soluble in water.

[0122] Defined transition metal complexes (I) can be prepared by thefollowing processes.

[0123] For the neutral chelate complexes (p=0), the preparation iscarried out by exchange of weakly coordinating ligands, for example1,5-cyclooctadiene, benzonitrile or tetramethylethylenediamine, whichare bonded to the corresponding transition metal compounds, for exampletransition metal halides, transition metal (alkyl) (halides) ortransition metal-diorganyls, for the novel chelate ligands of theformula (III) having the meaning described above.

[0124] The reaction is carried out- in general in a polar solvent, forexample acetonitrile, acetone, ethanol, diethyl ether, dichloromethaneor tetrahydrofuran or a mixture therof, at from −78 to +60° C.

[0125] Furthermore, neutral metal complexes (I) in which L¹ and L² areeach carboxylate, e.g. acetate, can be prepared by reacting transitionmetal salts, such as Pd(OAc)₂, with the chelate ligands (III) describedin acetonitrile, acetone, ethanol, diethyl ether, dichloromethane,tetrahydrofuran or water at room temperature. Solvent mixtures may alsobe used here.

[0126] The reaction of the chelate complexes of the formula (I) withorganometallic compounds of groups IA, IIA, IVA and IIB, for example C₁-to C₆-alkyls of the metals lithium, aluminum, magnesium, tin, and zinc,is suitable as a further method of synthesis, formally charged inorganicligands L¹, L², as defined above, being exchanged for formally chargedaliphatic, cycloaliphatic or aromatic ligands L¹, L² likewise as definedabove. The reaction is carried out in general in a solvent, for examplediethyl ether or tetrahydrofuran, at from −78 to 65° C.

[0127] Monocationic complexes of the formula (I) (p=1) can be obtained,for example, by reacting (chelate ligand) metal (acetate) (organo) or(chelate ligand) metal (halo)(organo) complexes with stoichiometricamounts of a metal salt M′X. The reactions are carried out in general incoordinating solvents, for example acetonitrile, benzonitrile ortetrahydrofuran, at from −78 to 65° C.

[0128] It is advantageous if the metal salts M′X fulfil the followingcriteria. The metal M′ should preferably form sparingly soluble metalchlorides, for example silver chloride. The salt anion should preferablybe a non-nucleophilic anion X as defined above.

[0129] Suitable salts for the formation of cationic complexes are silvertetrafluroborate, silver hexafluorophosphate, silvertrifluoromethanesulfonate, silver perchlorate, silverpara-toluenesulfonate, silver trifluoroacetate and silvertrichloroacetate.

[0130] The dicationic complexes (p=2) are prepared similarly to themonocationic complexes except that in this case the (chelate ligand)metal (diacetate) and (chelate ligand) metal (dihalo) complexes are usedas the precursor instead of the (chelate ligand) metal (acetate)(organo) or the (chelate ligand) metal (halo) (organo) complexes.

[0131] The reaction of [Q₄M]X₂ with the chelate ligands defined at theoutset and of the formula (III) is suitable as a further process for thepreparation of the dicationic complexes (I). Here, Q are identical ordifferent weak ligands, for example acetonitrile, benzonitrile or1,5-cyclooctadiene, and M and X have the meanings defined above.

[0132] A preferred process for the preparation of the metal complexes ofthe formula (I) is the reaction of the dihalo metal precursor complexeswith silver salts containing noncoordinating anions.

[0133] The copolymerization of carbon monoxide and α-olefinicallyunsaturated compounds in the presence of the novel catalyst system iscarried out in an aqueous medium. The polymerization mixture ispreferably vigorously mixed in order to obtain reproducibly goodproductivities. Suitable stirring tools, such as anchor stirrers orhelical ribbon impellers, may be used for this purpose. Suitablestirring speeds are from 250 to 1100 rpm, preferably above 290 rpm.

[0134] The carbon monoxide copolymer can in principle be obtained by twodifferent procedures. In one preparation process, the abovementioneddefined transition metal complexes (I) are used. These complexes areprepared separately and are added as such to the reaction mixture orinitially taken in the reaction container. In a further preparationprocess, the components forming the catalytically reactive species areadded individually to the reaction mixture. In this in situ generationof the catalyst, in general the metal M in salt form or as a complexsalt is fed to the reaction vessel. Furthermore, the chelate ligandcompound (III) and, if required, an activator compound are added. Theaddition of the activator species can be dispensed with if the chelateligand (III) has radicals R¹ to R⁴ which have at least one free sulfo orcarboxyl group.

[0135] As a rule, the use of defined metal complexes (I) is associatedwith higher productivities than those of the in situ process. Suitableolefinically unsaturated monomer compounds in said processes for thepreparation of carbon monoxide copolymers are both pure hydrocarboncompounds and hetero atom-containing α-olefins, such as (meth)acrylatesor (meth)acrylamides and homoallyl or allyl alcohols, ethers or halides.Among the pure hydrocarbons, C₂- to C₂₀-1-alkenes are suitable. Amongthese, the low molecular weight α-olefins, e.g. α-olefins of 2 to 8carbon atoms, such as ethene, propene, 1-butene, 1-pentene, 1-hexene or1-octene, are noteworthy. It is of course also possible to use cylicolefins, e.g. cyclopentene, aromatic olefin compounds, such as styreneor α-methylstyrene, or vinyl esters, such vinyl acetate. Ethene orpropene, in particular ethene, or a mixture of ethene with a lowmolecular weight α-olefin, such as propene or 1-butene, is particularlypreferably used.

[0136] The molar ratio of carbon monoxide to α-olefin or to a mixture ofα-olefins is as a rule from 5:1 to 1:5, usually from 2:1 to 1:2.

[0137] The copolymerization temperature is in general adjusted to from 0to 200° C., copolymerization preferably being effected at from 20 to130° C. The pressure is in general from 2 to 300, in particular from 20to 220, bar.

[0138] Suitable activator compounds can be used for activating thecatalyst. Suitable activator compounds are both mineral protic acids andLewis acids. Suitable protic acids are, for example, sulfuric acid,nitric acid, boric acid, tetrafluoroboric acid, perchloric acid,p-toluenesulfonic acid, trifluoroacetic acid, trifluoromethanesulfonicacid and methanesulfonic acid. p-Toluenesulfonic acid andtetrafluoroboric acid are preferably used.

[0139] Suitable Lewis acids are, for example, boron compounds, such astriphenylborane, tris(pentafluorophenyl)borane, tris(p-chlorophenyl)borane or tris(3,5-bis(trifluoromethyl)phenyl)borane, oraluminum, zinc, antimony or titanium compounds having a Lewis acidcharacter. Mixtures of protic acids or Lewis acids and protic and Lewisacids as mixture may be used.

[0140] The molar ratio of activator to metal complex (I), based on theamount of metal M, is in general from 60:1 to 1:1, preferably from 25:1to 2:1, particularly preferably from 12:1 to 3:1 where the functionalgroups of the radicals R¹ to R⁴ are not sulfo or carboxylfunctionalities. Of course, activator compound b) can be added to thepolymerization mixture also in the case of metal complexes havingchelate ligands which carry the abovementioned functional acid groups.

[0141] The carbon monoxide copolymerization can be carried out eitherbatchwise, for example in a stirred autoclave, or continuously, forexample in a tube reactor, loop reactor or stirred kettle cascade.

[0142] In the novel polymerization process in an aqueous medium, averagecatalyst productivities which are in general based on 0.5 kg of polymerper g of metal per h are obtained. Productivities greater than 0.7 kg ofpolymer per g of metal per h can also be reproducibly achieved.

[0143] With the aid of the novel catalyst systems, the use ofhalogenated or aromatic hydrocarbons is avoided. Moreover, expensiveseparation operations are dispensed with. The novel processesaccordingly provide an economical route for the simple preparation oflinear, alternating carbon monoxide copolymers. Finally, the catalystsobtainable by the novel processes have a constantly high averagecatalyst activity even after a reaction time of several hours.

[0144] The examples which follow illustrate the invention.

EXAMPLES I) Preparation of the Chelate Ligand Compounds

[0145] General Procedure

[0146] i) Preparation of Propane-1,3-bis(di-ethyl phosphonite)

[0147] Triethyl phosphite (696 ml) was added to 1,3-dibromopropane(102.5 ml) and the mixture was heated slowly to 140° C. The resultingbromoethane was removed by distillation. After the evolution ofbromoethane had declined, the reaction temperature was increased to 155°C. and the reaction was kept at this temperature for 24 hours. Furthertriethylphosphite (696 ml) was added dropwise and the reaction wasstopped after a further 24 hours by separating off excess triethylphosphite by distillation. Monosubstituted product was removed bydistillation at 150° C. under greatly reduced pressure. The remainingdistillation residue was propane-1,3-bis(diethyl phosphonite). Yield:86%.

[0148] ii) Preparation of 1,3-diphosphinopropane

[0149] A solution of propane-1,3-bis(diethyl phosphonite) (103.3 g) inabsolute diethyl ether (100 ml) was slowly added at 0° C. to asuspension of LiAlH₄ (25 g) in diethyl ether (200 ml). After the end ofthe addition, the reaction temperature was brought to room temperatureand the reaction was stirred for 16 hours at this temperature. Tohydrolyze excess LiAlH₄, degassed and argon-saturated 6 molarhydrochloric acid was slowly added. The organic phase separated off wasdried over sodium sulfate. The aqueous phase was thoroughly mixed withdiethyl ether and the diethyl ether phase was dried over sodium sulfateafter phase separation and was combined with the abovementioned organicphase. 1,3-Diphosphinopropane was obtained by distillation at 140° C.under atmospheric pressure. Yield: 61%.

[0150] iii) Preparation of Water-Soluble Chelate Ligand CompoundsBis(di-7-hydroxyheptyl)phosphinopropane, 1,3-diphosphinopropane (1.08 g)and 6-hepten-1-ol (44 mmol), which was repeatedly degassed and saturatedwith argon, were exposed to UV light from a high-pressure mercury lampfor 24 hours in a Schlenk-type quartz tube. In the case of higherolefins, the reaction vessel was additionally heated in order to reducethe viscosity of the reaction mixture. By separating off the excessolefin component by distillation, the desired chelate ligand compoundwas obtained virtually quantitatively.

[0151] Bis(di-5-hydroxypentyl)-, bis(di-6-hydroxyhexyl)-,bis(di-8-hydroxyoctyl)- andbis(di(3-hydroxycyclopentyl)propyl)phosphinopropane were obtainedsimilarly to the abovementioned method.

[0152] The starting compounds 1-pentenol, 1-hexenol and3-hydroxy-3-cylopentylpropene were obtained as follows:

[0153] 4-Penten-1-ol was prepared from 4-pentenoic acid, commerciallyavailable from Aldrich, by means of LiAl₄ reduction. 6-Heptenoic acidand 7-octenoic acid were converted into 6-hepten-1-ol and 7-octen-1-ol,respectively, in a similar manner.

[0154] 5-Hexen-1-ol was obtained from Fluka and was used without furtherpurification.

[0155] 3-Hydroxy-3-cyclopentylpropene was prepared from allylmagnesiumchloride and cyclopentane via a Grignard reaction.

II) Preparation of Defined Transition Metal Complexes

[0156] i) Preparation of[1,3-bis(di-5-hydroxypentyl)phosphino-propane]palladium(II) acetate

[0157] 0.9 g of 1,3-bis(di-5-hydroxypentyl)phosphino propane wasdissolved in 10 ml of repeatedly degassed and argon-saturated ethanoland slowly added dropwise to a solution of palladium(II) acetate (0.44 gin 15 ml of degassed, argon-saturated acetonitrile). To complete thereaction, stirring was continued for a further 20 minutes at roomtemperature. The solvent mixture was removed under reduced pressure andthe defined Pd complex was isolated as a highly viscous, brown-yellowoil.

[0158] ii) Preparation of[1,3-bis(di-6-hydroxyhexyl)phosphinopropane]palladium(II) acetate

[0159] The reaction was carried out similarly to II) i). The chelateligand used was 1,3-bis(di-6-hydroxyhexyl)phosphinopropane.

[0160] iii) Preparation of[1,3-bis(di(3-hydroxycyclopentyl)propyl)phosphinopropane]-palladium(II)acetate

[0161] A mixture of1,3-bis(di(3-hydroxycyclopentyl)propyl)phosphinopropane in 20 ml ofdichloromethane was added dropwise to a solution of 0.25 g ofpalladium(II) acetate in 20 ml of acetonitrile at room temperature.After stirring at room temperature for 16 hours, the solvent mixture wasremoved under reduced pressure. The desired Pd complex was isolated as ared solid.

III) Copolymerization of Carbon Monoxide and Ethene

[0162] Distilled water (100 ml), the desired amount of[1,3-bis(di-6-hydroxyhexyl)phosphinopropane]palladium(II) acetate andp-toluenesulfonic acid (five times the molar amount, based on the amountof catalyst used) were introduced into a 300 ml autoclave. The reactionvessel was first evacuated and was flooded with nitrogen. The nitrogenatmosphere was displaced by a 1:1 carbon monoxide/ethene mixture and thepolymerization was carried out at the desired pressure and the desiredtemperature over a preselected period at a stirrer speed of 300 rpm. Thereaction conditions were kept constant during the polymerization. Thereaction was stopped by cooling and letting down the pressure on thereaction vessel. The copolymer isolated by filtration was washed withmethanol (500 ml) and acetone (200 ml) and dried at 80° C. over a periodof 5 hours under greatly reduced pressure.

[0163] The copolymerization parameters and results are shown in Table 1below: Amount of Dura- Pres- Activity Viscosity catalyst tion sure Temp.[kg (PK)^(a))/ VZ^(b)) Exp. [mmol] [h] [bar] [° C.] g (Pd) /h] [ml/g] 10.009 5 80 80 0.542 170 2 0.017 5 80 60 0.366 667 3 c) 0.01 5 80 800.013 n.d.^(d)) 4 0.01 1 60 90 0.761 n.d.^(d))

We claim:
 1. A catalyst system for the copolymerization of carbonmonoxide and α-olefinically unsaturated compounds, containing, asessential components, a) a metal complex of the formula (I)

 where G is —(CR^(b) ₂)_(r)—, —(CR^(b) ₂)_(s)—Si(R^(a))₂—(CR^(b)₂)_(t)—, —A′—O—B′— or —A′—Z(R⁵)—B′— R⁵ is hydrogen, or is C₁- toC₂₈-alkyl, C₃- to C₁₄-cycloalkyl, C₆- to C₁₅-aryl or alkylaryl where thealkyl radical is of 1 to 20 carbon atoms and the aryl radical is of 6 to15 carbon atoms, each of which is unsubstituted or substituted byfunctional groups based on the elements of groups IVA, VA, VIA or VIIAof the Periodic Table of Elements, or is —N(R^(b))₂, —Si(R^(c))₃ or aradical of the formula II

 where q is an integer from 0 to 20 and the further substituents in (II)have the same meanings as in (I), A′ and B′ are each —(CR^(b) ₂)_(r′)—,—(CR^(b) ₂)_(s)—Si(R^(a))₂—(CR^(b) ₂)_(t)—, —N(R^(b))—, an r′-, s- ort-atom component of a ring system or, together with Z, an (r′+1)-,(s+1)- or (t+1)-atom component of a heterocyclic structure, R^(a)independently of one another, are each C₁- to C₂₀-alkyl, C₃- toC₁₀-cycloalkyl, C₆- to C₁₅-aryl or alkylaryl where the alkyl moiety isof 1 to 10 carbon atoms and the aryl moiety is of 6 to 15 carbon atoms,R^(b) is the same as R^(a) or is hydrogen or Si(R^(c))₃, R^(c) is C₁- toC₂₀-alkyl, C₃- to C₁₀-cycloalkyl, C₆- to C₁₅-aryl or alkylaryl where thealkyl moiety is of 1 to 10 carbon atoms and the aryl moiety is of 6 to15 carbon atoms, r is 1, 2, 3 or 4 r′ is 1 or 2, s and t are each 0, 1or 2, where 1<s+t<3 Z is a nonmetallic element from group VA of thePeriodic Table of Elements, M is a metal selected from the group VIIIB,IB or IIB of the Periodic Table of Elements, E¹ and E² are each anonmetallic element from group VA of the Periodic Table of Elements, R¹to R⁴ are each linear or branched C₂- to C₂₈-alkyl, C₃- toC₁₄-cycloalkyl or alkylaryl where the alkyl moiety is of 1 to 28 carbonatoms and the aryl moiety is of 6 to 15 carbon atoms, each of which issubstituted by at least one polar protic or ionic functional group basedon elements of groups IVA to VIA of the Periodic Table of Elements, L¹and L² are formally charged or neutral ligands, x are formallymonovalent or polyvalent anions, p is 0, 1, 2, 3 or 4, m and n are each0, 1, 2, 3 or 4, and p=m×n, and b) if required, one or more Lewis orprotic acids or a mixture of Lewis and protic acids.
 2. A catalystsystem as claimed in claim 1, wherein R¹ to R⁴ are linear, branched orcarbocycle-containing C₂- to C₂₈-alkyl units or C₃- to C₁₄-cycloalkylunits which have at least one terminal or internal hydroxyl, amino acid,carboxyl, phosphoric acid, ammonium or sulfo group, or alkylaryl wherethe alkyl moiety is of 1 to 28 carbon atoms and the aryl moiety is of 6to 15 carbon atoms, the alkyl or aryl moiety being substituted by atleast one hydroxyl, amino acid, carboxyl, phosphoric acid, ammonium orsulfo group.
 3. A catalyst system as claimed in claim 1 or 2, whereinthe Lewis acid used is boron trifluoride, antimony pentafluoride or atriarylborane and the protic acid used is sulfuric acid,p-toluenesulfonic acid, tetrafluoroboric acid, trifluoromethanesulfonicacid, perchloric acid or trifluoroacetic acid.
 4. A catalyst system forthe copolymerization of carbon monoxide and α-olefinically unsaturatedcompounds as claimed in claim 1, containing, as an essential component,a metal complex of the formula (I)

where G is (CR^(b) ₂)_(r)—, —(CR^(b) ₂)_(s)—Si(R^(a))₂—(CR^(b) ₂)_(t)—,—A′—O—B′— or —A′—Z(R⁵)—B′—, R⁵ is hydrogen or is C₁- to C₂₈-alkyl, C₃-to C₁₀-cycloalkyl, C₆- to C₁₅-aryl or alkylaryl where the alkyl radicalis of 1 to 20 carbon atoms and the aryl radical is of 6 to 15 carbonatoms, each of which is unsubstituted or substituted by functionalgroups based on the elements of groups IVA, VA, VIA or VIIA of thePeriodic Table of Elements, or is —N(R^(b))₂, —Si(R^(c))₃ or a radicalof the formula Formel II

 where q is an integer from 0 to 20 and the further substituents in (II)have the same meanings as in (I), A′ and B′ are each —(CR^(b) ₂)_(r′)—or —(CR^(b) ₂)_(s)—Si(R^(a))₂—(CR^(b) ₂)_(t)— or —N(R^(b))—, an r′-, s-or t-atom component of a ring system or, together with Z, an (r′+1)-,(s+1)- or (t+1)-atom component of a heterocyclic structure, R^(a)independently of one another, are each C₁- to C₂₀-alkyl, C₃- toC₁₀-cycloalkyl, C₆- to C₁₅-aryl or alkylaryl where the alkyl moiety isof 1 to 10 carbon atoms and the aryl moiety is of 6 to 15 carbon atoms,R^(b) is the same as R^(a) or is hydrogen or Si(R^(c))₃, R^(c) is C₁- toC₂₀-alkyl, C₃- to C₁₀-cycloalkyl, C₆- to C₁₅-aryl or alkylaryl where thealkyl moiety is of 1 to 10 carbon atoms and the aryl moiety is of 6 to15 carbon atoms, r is 1, 2, 3 or 4 and r′ 1 or 2, s and t are each 0, 1or 2, where 1<s+t<3 z is a nonmetallic element from group VA of thePeriodic Table of Elements, M is a metal selected from the group VIIIB,IB or IIB of the Periodic Table of Elements, E¹ and E² are each anonmetallic element from group VA of the Periodic Table of Elements, R¹to R⁴ are each linear or branched C₂- to C₂₈-alkyl, C₃- toC₁₄-cycloalkyl or alkylaryl where the alkyl moiety is of 1 to 28 carbonatoms and the aryl moiety is of 6 to 15 carbon atoms, each of which issubstituted by at least one polar protic or ionic functional group basedon elements of groups IVA to VIA of the Periodic Table of Elements, L¹and L² are formally charged or neutral ligands, X are formallymonovalent or polyvalent anions, p is 0, 1, 2, 3 or 4, m and n are each0, 1, 2, 3 or 4, and p=m×n, and no external protic or Lewis acid b). 5.The use of a catalyst system as claimed in any of claims 1 to 4 for thepreparation of linear, alternating copolymers of carbon monoxide andα-olefinically unsaturated compounds in an aqueous medium.
 6. A processfor the preparation of linear, alternating copolymers of carbon monoxideand α-olefinically unsaturated compounds, wherein the copolymerizationis carried out in an aqueous medium in the presence of a catalyst systemas claimed in claims 1 to
 4. 7. A process for the preparation of linear,alternating copolymers of carbon monoxide and α-olefinically unsaturatedcompounds, wherein the monomers are copolymerized in an aqueous mediumin the presence i) of a metal M selected from the group VIIIB, IB or IIBof the Periodic Table of Elements, which is present in salt form or as acomplex salt, ii) a chelate ligand of the formula (III) (R¹)(R²)E¹—G—E²(R³) (R⁴), where G is —(CR^(b) ₂)_(r)—, —(CR^(b)₂)_(s)—Si(R^(a))₂—(CR^(b) ₂)_(t)—, —A′—O—B′— or —A′—Z(R5)—B′—, R⁵ ishydrogen or is C₁- to C₂₈-alkyl, C₃- to C₁₄-cycloalkyl, C₆- to C₁₅-arylor alkylaryl where the alkyl radical is of 1 to 20 carbon atoms and thearyl radical is of 6 to 15 carbon atoms, each of which is unsubstitutedor substituted by functional groups based on the elements of groups IVA,VA, VIA or VIIA of the Periodic Table of Elements, or is —N(R^(b))₂,—Si(R^(c))₃ or a radical of the formula IIa)

 where q is an integer from 0 to 20 and the further substituents in(IIa)) have the same meanings as in (III), A′ and B′ are each —(CR^(b)₂)_(r′)—, —(CR^(b) ₂)_(s)—Si(R_(a))₂—(CR^(b) ₂)_(t)—, —N(R^(b))—, anr′-, s- or t-atom component of a ring system or, together with Z, an(r′+1)-, (s+1)- or (t+1)-atom component of a heterocyclic structure,R^(a) independently of one another, are each C₁- to C₂₀-alkyl, C₃- toC₁₀-cycloalkyl, C₆- to C₁₅-aryl or alkylaryl where the alkyl moiety isof 1 to 10 carbon atoms and the aryl moiety is of 6 to 15 carbon atoms,R^(b) is the same as R^(a) or is hydrogen or Si(R^(c))₃, R^(c) is C₁- toC₂₀-alkyl, C₃- to C₁₀-cycloalkyl, C₆- to C₁₅-aryl or alkylaryl where thealkyl moiety is of 1 to 10 carbon atoms and the aryl moiety is of 6 to15 carbon atoms, r is 1, 2, 3 or 4, r′ is 1 or 2, s and t are each 0, 1or 2, where 1<s+t<3 Z is a nonmetallic element from group VA of thePeriodic Table of Elements, E¹ and E² are each a nonmetallic elementfrom group VA of the Periodic Table of Elements, and R¹ to R⁴ are eachlinear or branched C₂- to C₂₈-alkyl, C₃- to C₁₄-cycloalkyl or alkylarylwhere the alkyl moiety is of 1 to 28 carbon atoms and the aryl moiety isof 6 to 15 carbon atoms, each of which is substituted by at least onepolar protic or ionic functional group based on elements of groups IVAto VIA of the Periodic Table of Elements, and iii) if required, one ormore Lewis or protic acids or a mixture of Lewis and protic acids.